I've got an original iPhone its from the US but im now using it in the UK on o2. It gets really poor signal usually no service when my old phone got full signal in the same place. I've tried reseating the sim, reseting the network settings and restoring the iPhone.

Does anyone have any ideas how i can improve the signal. I dont really want a signal booster as its mostly when im outside i dont get signal.

Incidently i get full signal when im fairly close to the tower.

Thanks
Jack Dunn